vt_buffer.h

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/*
 *  include/linux/vt_buffer.h -- Access to VT screen buffer
 *
 *  (c) 1998 Martin Mares <[email protected]>
 *
 *  This is a set of macros and functions which are used in the
 *  console driver and related code to access the screen buffer.
 *  In most cases the console works with simple in-memory buffer,
 *  but when handling hardware text mode consoles, we store
 *  the foreground console directly in video memory.
 */

#ifndef _LINUX_VT_BUFFER_H_
#define _LINUX_VT_BUFFER_H_


#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_MDA_CONSOLE)
#include <asm/vga.h>
#endif

#ifndef VT_BUF_HAVE_RW
#define scr_writew(val, addr) (*(addr) = (val))
#define scr_readw(addr) (*(addr))
#define scr_memcpyw(d, s, c) memcpy(d, s, c)
#define scr_memmovew(d, s, c) memmove(d, s, c)
#define VT_BUF_HAVE_MEMCPYW
#define VT_BUF_HAVE_MEMMOVEW
#endif

#ifndef VT_BUF_HAVE_MEMSETW
static inline void scr_memsetw(u16 *s, u16 c, unsigned int count)
{
    count /= 2;
    while (count--)
        scr_writew(c, s++);
}
#endif

#ifndef VT_BUF_HAVE_MEMCPYW
static inline void scr_memcpyw(u16 *d, const u16 *s, unsigned int count)
{
    count /= 2;
    while (count--)
        scr_writew(scr_readw(s++), d++);
}
#endif

#ifndef VT_BUF_HAVE_MEMMOVEW
static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count)
{
    if (d < s)
        scr_memcpyw(d, s, count);
    else {
        count /= 2;
        d += count;
        s += count;
        while (count--)
            scr_writew(scr_readw(--s), --d);
    }
}
#endif

#endif